1. Field of the Invention
The present invention relates to a semiconductor device manufacturing technology or more particularly a heat processing technology for processing a substrate to be processed while being heated up by heating elements in a processing chamber and also relates to a heating apparatus, a substrate processing apparatus employing the heating apparatus, a method of manufacturing semiconductor devices, and an insulator.
2. Description of the Related Art
FIG. 1 is a schematic cross sectional view of a processing furnace 500 equipped with a conventional heating apparatus. The conventional heating apparatus comprises a metallic casing 501 arranged of substantially a tubular shape with the upper end closed, a thermal insulator material 502 arranged of substantially a tubular shape and disposed at the inside of the casing 501, and heating wires 503 mounted to the inner wall of the thermal insulator material 502. The heating apparatus contains a thermal equalizer tube 504 and a reactor tube 505 which acts as a processing chamber and the action of heating up a wafer 506 in a given manner is carried out in the reactor tube 505.
It has been demanded in the metallic wiring process (Cu annealing etc.) to decrease the processing temperature (to not higher than 300° C.) and improve the throughput. Therefore, the shortening of the temperature increase and decrease of the wafer is essential. However, for responding to the above demand, such a conventional heating apparatus as shown in FIG. 1 employs a large amount of thermally insulating materials for permitting the use of heaters in middle and high temperature ranges, hence being low in the temperature increase and decrease response and hardly improving the throughput. It is thus desired to provide an improved heating apparatus which is high in the thermal response.
Disclosed in Patent Citation 1 is a substrate processing apparatus which allows its heating space to be cooled down rapidly with the cooling gas supplied through the pins which are provided to extend through the heating elements. The thermal response in the heating apparatus can thus be improved by modifying the cooling property. Another substrate processing apparatus disclosed in Patent Citation 2 comprises heating elements disposed in a heater unit to surround the processing chamber, a first reflector disposed to surround the heating elements, and a second reflector disposed to surround the first reflector as spaced at the outer side by a distance from the first reflector so that the efficiency of increasing and decreasing the temperature in the processing chamber can be improved.
It is essential for improving the thermal response in the heating apparatus to ease the adverse effect of reflected or radiated heat on the temperature detector in order to increase the accuracy of the temperature measurement. Patent Citation 3 has proposed, without significant success, some arrangements applicable to the heating apparatus shown in FIG. 1. Patent Citation 4 discloses that the thermally insulating materials for inhibiting the radiation of heat at the cooling passage of the temperature detector are disposed separately while the accuracy of the temperature measurement remains not improved.
Patent Citation 1: WO2007/023855.
Patent Citation 2: Japanese Patent Laid-open Publication No. 2004-311648.
Patent Citation 3: Japanese Patent Laid-open Publication No. 2004-228381.
Patent Citation 4: Japanese Patent Laid-open Publication No. (Heisei) 7-18446.